Drum type sander



Aug. 8, 1933. P. A. SOLEM 1,921,995

DRUM TYPE SANDER Original Filed March 19, 1927 2 Sheets-Sheet, l

Aug. 8, 1933. P. A. SOLEM DRUM TYPE SANDER Original Filed March 19, 1927 2 Sheets-Sheet, 2

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22 Claims.

This application is a division of my application Serial No. 176,618, filed March 19, 1927, which resulted in Patent 1,718,839, issued June 25, 1929.

This invention relates to drum type sanders for wood-working and has for its principal object the novel arrangement and construction of parts in the top portion of the machine for the purpose of securing better exhausting of the dust from the drums and thereby increase the efficiency of operation as well as improve the character of the finish produced on the work.

According; to my invention, instead of employing a single dust hood for the plurality of drums, as is commonly done, I have so constructed the machine and have provided a plurality of hoods so located that the dust is exhausted from the back as well as the front of each drum with a view to removing substantially all of the dust arising from the operation of the drums. With this arrangement such dust as remains on the surface of a drum after passing one exhaust opening is more or less certain of removal through the other exhaust opening especially since the dust particles are subjected not only to a considerable centrifugal action in the operation of the drums but a powerful draft as well.

The construction of the machine briefly stated involves the use of top plates which, as described in my other application, are secured at opposite ends to the journal bearings of the drums and serve to interconnect the same, the said plates overlying the drums and being disposed in abutting relation with one another, also as fully set forth in said application. The plates are conformed to provide narrow elongated openings between the abutting portions thereof directly over the pressure bars disposed between the drums, so that each opening is in communication with the back of one drum and the front of the next adjacent drum. In like manner the top plates at the front and rear ends of the machine provide openings where they abut with extensions of the foremost and rearmost pressure bars so as to remove the dust from in front of the foremost drum and from behind the rearmost drum. The top plates have central longitudinal openings therein through which enough of each of the drums is exposed to permit replacing the abrasive covering on the drums front and rear exhaust openings thus tending to pick up and entrain any dust particles on the drums. The top portion of the machine is constructed so that the drums are substantially entirely inclosed except for the aforesaid air intake openings so that practically all of the air drawn in because of the suction in the dust hoods enters at the points referred to and powerful drafts are insured to pick up the dust tending to adhere to the drums.

The invention is more fully described in the following specification in which reference is made to the accompanying drawings wherein:

Fig. 1 is a side view of a sander of the endless bed type wherein the entire top portion has been F improved in accordance with my invention,

2 is a plan view of Fig. 1 showing only the right hand half of the machine without the bed, and

Fig. 3 is a central vertical section through the top portion of the machine with a view to illustrating tobest advantage my improved method and means for exhausting the dust from the drums as well as from a work dusting brush operated in connection therewith.

Throughout the views the same reference numerals are applied to corresponding parts.

Drum type sanders are usually constructed with a base 5 having heavy upright side frame pieces 6 suitably fixed together in spaced relation. The frame provides supports for ways over which an endless bed 7 is arranged to move, the bed consisting of steel slats with rubber pads secured thereon and the slats being secured on roller chains operating on sprockets mounted on bearings at 8 and '9 at opposite ends of the machine. The bed is driven through suitable transmission from a shaft 10 which in turn is driven by a motor supported on a bracket at the far side of the machine. A pulley 11 on the shaft 10 is provided for driving pulleys 12 and 13 which operate brushes for cleaning the stock passing through the machine and for cleaning the bed 7. The brush for cleaning the stock is indicated at 14 and will receive further mention hereinafter. The belt 15 passing about the pulleys referred to has an idler take-up pulley 16. A plurality of rotary abrading drums 17, 18 and 19 operate over the bed 7 and are provided with individual driving motors (not shown) arranged to be controlled singly or collectively to give aone, two or three drum machine as desired, and to permit any one or more or all of the motors being started or stopped as desired. Usually the front drum of the set, namely the drum 17, is

given simple rotation for the initial rough finishing cut inasmuch as it operates at the intake end of the machine. The other drums which are rearwardly located with reference to the drum 1'! are arranged to have endwise oscillation or reciprocation during rotation in order that the grade of finish on the work may be improved by avoiding: the drawing or stringing out of the fibers of the wood in a loose fuzz or fur. Thus, the drums 18 and 19 are oscillated by rockerarms or beams 20 which have a suitable thrust bearing connection with the projecting journals of the drums, as at 21. The rocker arms are suitably oscillated on their mountings 22 by cams on the shaft which is suitably driven through a direct gearing connection with the shaft 10. In this way the oscillating motion of the drums 1S and 19 occurs only during the feeding movement of the endless bed '7, that is, during the normal operation of the machine. Each of the drums has it projecting journals received in bearings the drums are individually adjustable as to elevation for light or heavy cuts by the turning of jack screws 25 provided in connection with the journal bearings 24 of each drum. The pair of jack screws for each drum are usually interconnected for simultaneous operation so as to elevate both ends of the drum to equal degree. For the most part, the foregoing arrangement is commonly employed in sanding machines of the drum type and no invention is laimed therein except only insofar as the improvements hereinafter ferred to rely upon these features in the new combinations and arrangements which I have evolved.

Referring now more particularly to Fig. 1, it will be observed that the top of the side frame pieces 6 is milled off fiat from end to end, as indicated at 26. The tops of the bosses 27 are also preferably milled off in the same operation. The latter provide guides for depending portions 28 of the journal bearings 24 to permit vertical movement of the journal bearings when the jack screws 25 are adjusted. Pad portions 29 of pressure bars 30 disposed between the drums 17 and 18 and between the drums 18 and 19 are arranged to be bolted, as indicated at 31, onto the flat top surface 26 of the side frame pieces. The corners of the pads 29 are relieved, as indicated at 32, to admit a shank 33 which depends from each of the journal bearings 24 and is formed integral with the portions 28, previously referred to. Two other pressure bars 34 and 35 are provided in front of the front drum 17 and behind the rearmost drum 19, respectively, each having its pad portion 36 arranged to bolt on the flat top surface 26, as indicated at 3'7. Obiously it is a simple matter to place the parts referred to in their proper positions and to bolt the same in place. At this point, however, it will also be observed that the bolts 37 fit rather freely in their openings 38 provided therefor in the pads 36 to permit of a certain amount of jogging of the bars 34 and 35 one way or another for a purpose which will presently appear. The journal bearings 2% have walls 39 preferably formed integral therewith to enclose the sides of the drums and serve in the nature of guards. These side walls are flanged, as at 40, and provide a flat top surface for the bolting onto the bearings of top plates 41. These plates extend lengthwise of the drum and serve rigidly to interconnect the journal bearings 24 at the opposite ends of each or" the drums, the

plates being bolted to the flanges 40 formed integral with said hearings in the manner shown. The top plates also provi vertical bearing surfaces 42 on the fore and aft sides thereof. These bearing surraces on each of the plates 41 are arranged to be brought into close contact with similar bearing surfaces on adjoining plates, the plates being disposed in side to side relation in the manner shown. The engagement is such, however, as to permit of the vertical adjustment of one journal bearing relative to another. In other words, one top plate slides with respect to the other in the event one drum is adjusted relativ to another. Taking drum 18 as an example fo" the present it will be apparent that a threepoint support is provided for the journal bearing 24, the one point being directly beneath the journal bearing at bearing 27 and the other two points being fore and aft with r spect thereto at the surfaces 42. Obviously this makes for extreme ri idity and there is little likelihood of vibration chattering of the drum in opera tion. Any fore and aft thrust on the journal bearing incident to the operation of the drum is assumed mainly by the abutment of the fore and aft vertical bearing surfaces. As respects the group of drums the journal bearings thereof obviously have mutual. support one from another by reason of the inter-engagement of the vertical bearing surfaces. The ressure bars 34 and 35 are extended into the plane of the top plates 11 and provide vertical end bearings at 43 and 44, respectively, arranged to be brought up against the group of inter-supported bearings from in fron and from behind to support the group as a unit against fore and aft play so as further to insure rigidity in the mounting of the drums and eliminate chattering and vibration in operation thereof. The purpose in providing for a slight jogging of the pressur bars 34 and 35 will now be apparent. This jogging takes care of any discrepancy in the machining of the plates 41 or discrepancies arising from other causes and permits the group of parts to be brought together 111.20 snug engagement for the purpose referred to. The threepoint supporting of each pair of journal bearings is obviously unaffected by vertical adjustment thereof and each drum is supported as well in one state of adjustment as in another. The construction above described is covered in the patent mentioned above and has been referred to merely for ie purpose of conveying a better understanding of the features with which the present application is more particularly concerned. In passing it will be noted that the walls 39 substantially inclose the drums on the sides, that is, they prevent the escape of dust from the sides of the machine and likewise to a certain extent prevent air being drawn in at these points because of suction in the dust hoods presently to be described, the object being to cause the air to be drawn in across the periphery of the drums in a certain novel manner as hereinafter described so as to insure the removal of any dust tending otherwise to adhere to th drums.

Referring now more particularly to Figs. 2 and 3 wherein I have illustrated the novel meth od and means with which the present invention is particularly concerned for exhausting the dust from the drums, it will be observed that the top plates ll are conformed to the periphery of the drums and extend in between the latter over the tops of the pressure bars 30 as shown at 45. This leaves a narrow space between the plates and the periphery of the drums for the passage of air in sheets the full length of the, drums, the air being admitted through central longitudinal openings 45a provided in the plates between the front and rear dust exhaust openings 48 in turn provided between the abutting faces of the plates and arranged to communicats with both sides of the pressure bars to exhaust dust from behind the drum 17 and the front of the drum 18 in one case, and from behind the drum 18 and the front of the drum 19 in the other case. According to the present invention, instead of using a single hood in connection with all of the drums for exhausting the dust arising from the operation thereof, a plurality of individual hoods or exhaust conduits are provided, as indicated in dotted lines at 47, fitting on hollow necks i8 provided at the juncture of the plates 41 about the exhaust openings 46, and also communicating with a dust exhaust opening 49 provided at the front of the machine between the plate 41 and the pressure bar 34, the said exhaust opening communicating with the front of the drum l7, and also with another exhaust opening 50 provided at the rear of the machine between the pressure bar and the plate 41 abutting the same, the last mentioned opening being in communication with the back of the drum 19. The openings 46, 49 and 50 are obviously fairly narrow so that, although they extend the full length of the drums, each opening has a cross-sectional area approximately equal to the crosssectional area of the hood 4? connected therewith. Thus a reduction in pressure in the dust hoods results in the drawing in of air at a uniform rate the full length of the drums through the openings 45a in the top plates in sheets passing through the spaces between the peripheries of the drums and the conformed portions of the plates. The result is that any dust tending to adhere to the drums, in addition to being acted'upon by centrifugal force due to the rotation of the drums, is acted upon by drafts of air passing directly over the peripheries of the drums, and if the dust is not removed at the front exhaust opening it is more or less certain of beiir removed at the rear exhaust opening. Much greater abrading efficiency is therefore secured and a correspondingly improved character of finish is produced on the work. Attention is also called to the fact that the rearmost hood 47 in addition to having communication with the back of the drum 19 through the opening 50 is in communication through a passage 51 with a brush chamber 52 provided in the pressure bar 35 for the reception of the work dusting brush 14. Thus the exhaust opening 50 serves to remove dust from the back of the drum l9 and the front of the brush 14. The work leaving the machine is bound to be cleaner as a result of having been brushed with a clean brush.

It is believed the foregoing description conveys a clear understanding of my invention and of its various objects and advantages. While reference has been made to certain specific details of construction and arrangement it should be evident that various changes would naturally occur to one skilled in the art to which the invention relates. For that reason all legitimate modifications and adaptations are intended to be covered in the appended claims.

I claim:

1. In a machine of the character described,

the combination of frame members, two or more rotary abrading drums mounted on said frame members in parallel relation, pressure bars disposed between the drums, and a top wall extending over a pressure bar between two adjoining drums, said wall having an exhaust opening communicating with both sides of the pressure bar so as to exhaust the dust from the back of one drum and the front of the next drum.

2. In a machine of the character described, the combination of frame members, two or more rotary abrading drums disposed in spaced parallel relation and supported on the frame members, and a wall extending between the tops of two adjoining drums, said wall being provided with a dust exhaust opening for removing dust from the front of one drum and the back of the other.

3. In a machine of the character described, the combination of frame members, a rotary abrading drum-supported on said frame members, and walls enclosing portions of the drum at the front and back thereof, said walls being each provided with a dust exhaust opening, the forward opening exhausing the dust from the front of the drum, and the rearward opening exhausting any dust which may remain on'any given portion of the surface of the drum after passing by the forward opening.

4. In a drum type sanding machine, the combination with a frame having a'work feeding bed, and a rotary abrading drum mounted on the frame to operate on the work, of means enclosing the front of the drum, a dust ex haust conduit communicating with said means arranged to have a reduction in pressure created therein so as to withdraw dust from in front of the drum, and another means rearwardly displaced with respect to the conduit serving to enclose a top portion of the drum, the latter means being in communication with the conduit whereby to have air drawn in over the periphery of the drum and. tend toentrain any. dust picked up from the periphery of the drum, the said dust exhaust conduit having a narrow intake opening elongated to substantially the full length of the drum, and the said last mentioned means being arranged to admit air in a sheetthe full length of the drum substantially as and for the purpose described.

5. In a drum type sanding machine, the combination with a frame having a work feeding bed, and a rotary abrading drum mounted on the frame to operate on the work, of means enclosing the front of the drum, means enclosing the back of the drum, separate dust conduits communicating with the two means'arranged to have a reduction in pressure created therein to draw in dust from in front and from behind the drum in the operation of the latter, and means between the conduits serving tov enclose portions of the top of the drum in the vicinity of the conduits, said means being in communication with the conduits whereby air is arranged to be drawn over the periphery of the drum at the front and back tending to entrain dust picked up from the drum.

6. A structure as set forth in claim 5 wherein each of the conduits has a narrow intake opening elongated substantially to the full length of the drum and wherein the last mentioned means is arranged to admit thin sheets of air the full length of the drum substantially as and for the purpose described.

'7. In a drum type sanding machine, the combination with'a frame having a work feeding bed, and a rotary abrading drum mounted on the frame to operate on the work, of means enclosing the back of the drum, a dust exhaust conduit communicating with said means arranged to have a reduction in pressure created therein so as to withdraw dust from in back of the drum, and another means forwardly displaced with respect to the conduit serving to enclose a top portion of the drum, the latter means being in communication with the conduit whereby to have air drawn in over the periphery of the drum and tend to entrain any dust picked up from the periphery of the drum, the said dust exhaust conduit having a narrow intake opening elongated to substantially the full length of the drum, and the said last mentioned means being arranged to admit air in a sheet the full length of the drum substantially as and for the purpose described.

8. In a machine of the character described, the combination of frame members, two or more rotary abrading drums mounted on said frame members in parallel relation, pressure bars disposed between the drums and in front of the foremost and behind the rearmost drum, and a top wall extending close down over the tops of the drums and provided with exhaust openings at the front and rear ends thereof each extending lengthwise of the drums, the one communicating with the space between the front of the foremost drum and the front pressure bar, and the other communicating with the space between the back of the rearmost drum and the rear pressure bar, a separate dust exhaust conduit for each of. said openings, said wall having one or more intermedia e exhaust openings, each of said openings communicating with both sides of one of the intermediate pressure bars so as to jointly exhaust the dust from the back of.

one drum and the front of the next drum, and a separate dust exhaust conduit for each of said last mentioned openings.

9. In a machine of the character described, the combination of frame members, two or more rotary abrading drums mounted on said frame members in parallel relation, pressure bars disposed between the drums and in front of the foremost and behind the rearmost drum, and a top wall extending over the drums provided with exhaust openings at the front and rear ends thereof, the one communicating with the space between the front of the foremost drum and the front pressure bar, and the other communicating with the space between the back of the rearmost drum and the rear pressure bar, said wall having one or moreintermediate exhaust openings each communicating with both sides of one of the intermediate pressure bars so as to exhaust the dust from the back of one drum and the front of the next drum, and said top wall alsohaving air intake openings between the exhaust openings over the tops of the drums through which air is drawn over the periphery of the drum forwardly and rearwardly to the exhaust openings.

10. In a machine of the character described, the combination of frame members, two or more rotary abrading drums disposed in spaced parallel relation and supported on the frame members, means providing front and rear walls in front of the foremost and behind the rearmost drum and other walls to enclose the ends of the drums, and a top wall extending from the front sszrsss wall to the rear wall having openings through which the top of each of the drums is exposed and having other openings communicating with the spaces between the drums, the first mentioned openings constituting air intake openings, and the last mentioned openings constituting exhaust openings, the air being taken in over the top of each drum and passed forwardly and rearwardly over the periphery of the drums to the exhaust openings, whereby to remove dust from the front well as the back of each drum.

11. In a machine of the character described, the combination of frame members, a rotary abrading drum supported thereon, and walls enclosing the drum at the front, the back, as well as the ends and at least a portion of the top, there being a forward exhaust opening provided in said enclosure for the exhausting of the dust from the front of the drum and a rearward exhaust opening for exhausting dust from the back of the drum, as Well as an intermediate air intake opening between the exhaust openings over the top of the drum through which air is arranged to be taken in and passed forwardly and rearwardly over the periphery of the drum to the forward and rearward exhaust openings. 7

12. In a machine of the character described, the combination or" 'rame members, two or more rotary abrading drums disposed in spaced parallel relation and having end bearings for supporting-the same on the frame members, the said bea: h 's being arranged to be raised and lowered for raising and lowering the drums, top plates conformed to fit over the tops of the drums and fastened rigidly at the opposite ends thereof to the end bearings for up and down adjustment therewith, said top plates having fore and aft bearing surfaces disposed in contact with one another between the drums for the mutual lateral supp rt of the bearings, and abutments at the front and'back of the machine carried by the frame members and having contact with the front of the foremost top plate and the back of the real-most top plate respectively, whereby to provide lateral support for the groups of bearings, the top plates each having an opening substantially the full length of the drum associated therewith through which portion of the top of the drum is exposed and each top plate having the fore and aft bearing surfaces cut away to serve as exhaust openings adapted for connection with dust exhaust conduits, whereby air is taken in over the top of the drum and passed forwardly and rearwardly over the periphery of the drum to the exhaust openings to remove the dust from the back as well as the front of each drum.

13. A machine as set forth in claim 12, including pressure bars disposed between the drums and carried by the frame members, said pressure bars having the upper ends thereof made narrow and arranged to longitudinally divide the exhaust openings in the top plates disposed above the same, whereby each of these exhaust openings communicates on one side of the pressure bar associated therewith with the back of one drum, and on the other side of the pressure bar with the front of the next drum.

14. In a machine of the character described, the combination of frame members, two or more rotary abrading drums disposed in spaced parallel relation and supported on the frame members, and a wall extending between the.v tops of two adjoining drums, said wall being substantially Wedge-shaped in cross-section with the opposite sides of the wedge preferablyarcuate and disposed in slightly spaced relation to the peripheries of the drums to permit the intake of air in a sheet over the periphery of each of said drums, and said wall being pro-- vided with a dust exhaust opening for removing dust from the front of one drum and the back of the other.

15. A machine as set forth in claim 14, including a pressure bar disposed between the drums below said wall, said pressure bar being substantially wedge-shaped in cross-section with the opposite sides thereof preferably arcuate to conform to the peripheries of the drums and slightly spaced with reference thereto, the top of the pressure bar being made narrow and arranged to longitudinally divide the dust exhaust opening so as to provide for communication between the opening and the front of one drum on one side of the pressure bar and the back of the other drum on the other side of the pressure bar.

16. In a drum type sander, the combination of frame members, two or more rotary abrading drums disposed in spaced parallel relation and having end bearings for supporting the same on the frame members, the said bearings being arranged to be raised and lowered for raising and lowering the drums, enclosure walls for the sides of the drums on the end bearings, top plates conformed to fit over the tops of the drums and fastened rigidly at the opposite ends thereof to the bearings at the upper ends of the aforesaid walls, said top plates having fore and aft bearing surfaces disposed in contact with one another between the drums for the mutual lateral support of the bearings, and abutments at the front and back of the machine carried by the frame members and having contact with the front of the foremost top plate and the back of the rearmost top plate, respectively, whereby to provide lateral support for the groups of bearings, the top plates being formed to provide exhaust openings between the abutting bearing surfaces thereof reaching lengthwise of the drums, said exhaust openings.

being adapted for connection with dust exhaust conduits for the removal of dust from the back and front of each drum.

17. A machine as set forth in claim 16 wherein each of the top plates is further formed with an opening between the fore and aft bearing surfaces thereof extending lengthwise of the drum for exposure of a portion of the top of rotary abrading drums disposed in spaced parallel relation and having end bearings for supporting the same on the frame members, the said bearings being arranged to be raised and lowered for raising and lowering the drums, top

plates conformed to fit over the tops of the drums and fastened rigidly at the opposite ends thereof to the end bearings for up and down adjustment therewith, said top plates having fore and aft bearing surfaces disclosed in contact with one another between the drums for the mutual lateral support of the bearings, and abutments at the front and back of the machine carried by the frame members and having contact with the front of the foremost top plate and the back of the rearmost top plate respectively, whereby to provide lateral support for the groups of bearings, the top plates being formed to provide exhaust openings between the abutting bearing surfaces thereof reaching lengthwise of the drums, said exhaust openings being adapted for connection with dust exhaust conduits for the removal of dust from the back and front of each drum.

20 A machine as set forth in claim 19 including pressure bars disposed between the drums and carried by the frame members, said pressure bars having the upper ends thereof made narrower than the exhaust openings and arranged to longitudinally divide said openings,

whereby each of said openings communicates on one side of the pressure bar associated therewith with the back of one drum and on the other side with the front of the next drum.

21. In a machine of the character described, the combination of frame members, two or more rotary abrading drums disposed in spaced parallel relation and supported on the frame members, and a wall extending between the tops of two adjoining drums, said wall being substantially wedge-shaped incross-section with the opposite sides of the wedge disposed in slightly spaced relation to the peripheries of the drums to permit the intake of air in a sheet over the periphery of each of said drums, and said wall being provided with a dust exhaust opening for removing dust from the front of one drum and the back of the other.

22. A machine as set forth in claim 21, including a pressure bar disposed between the drums below said wall, said pressure bar being substantially wedge-shaped in cross-section with the opposite sides thereof slightly spaced with reference thereto, the top of the pressure bar being made narrow and arranged to longitudinally divide the dust exhaust opening so as to provide for communication between the opening and the front of one drum on one side of the pressure bar and the back of the other drum on the other side of the pressure bar.

PETER A. SOLEM.

CERTIFECATE 0F GQRRECTKON.

Patent No. 1,921,995. August 8, 1933.

PETER A. SGLEM.

It is hereby certified that error appears in the primed specification of the above numbered patent requiring correction as follows: Page 5, line 91, claim 19, for "disclosed" read "disposed"; and that the said Letters Patent should be read with this correction therein that the some may conform to the record of the case in the Patent Office.

Signed and sealed this 29th day oi August, A. D. 1933.

M. J. Moore.

(Seal) Acting Commissioner of Patents. 

